Snapshot A 60-year-old man is brought to the emergency department for confusion, cough, and diarrhea. He had recently attended a conference and stayed at an old hotel where other people reported similar symptoms. His past medical history includes chronic obstructive pulmonary disease and hypertension. He smokes 1 pack per day. On physical exam, his oxygen saturation is 92% on room air. There are fine crackles bilaterally on chest auscultation. A chest radiograph reveals diffuse patchy infiltrates. He is also found to have hyponatremia. A urine antigen test was sent for definitive diagnosis. Introduction Classification login to view 7 more bullets Epidemiology login to view 7 more bullets Pathogenesis login to view 2 more bullets Associated conditions login to view 6 more bullets Prognosis login to view 1 more bullet Presentation Symptoms login to view 12 more bullets Physical exam login to view 6 more bullets Imaging Chest radiography login to view 5 more bullets Studies Labs login to view 8 more bullets Making the diagnosis login to view 1 more bullet Differential Mycoplasma pneumoniae login to view 2 more bullets Treatment Medical login to view 6 more bullets Complications Respiratory failure